Question

Find the measures of two angles, one positive and one negative, that are coterminal with pi divided by five.

Answer 1

The given angle is π/5.

The coterminal angles differ from the given angle by 2π and -2π.
The lower coterminal angle is

`( \pi )/(5)-2 \pi = - (9 \pi )/(5)`
The higher coterminal angle is

`( \pi )/(5) +2 \pi = (11 \pi )/(5)`

Answer:
`- (9 \pi )/(5) . \, (11 \pi )/(5)`